Sunscreen – How Much Should I Use?

It was only recently (in the past few years) that I started paying attention to how much sunscreen to use to get the sun protection factor (SPF) on the bottle. It was a duh moment for me – obvious in hindsight but a complete blind spot up to that point. The kicker is, you don’t get the promised SPF unless you use the correct amount.

The Food and Drug Administration (FDA) requires sunscreens to be tested at 2mg/cm², which means two milligrams of sunscreen per square centimeter of skin.

Huh? You want me to do…math?

Okay, let me back up a step…You DO use sunscreen, don’t you? Every. Single. Day. Right?

I’m not judging you…but I’m inviting you to be a better version of yourself if you skip this step. I have loved ones who skip this, so I understand it’s common. Here’s the pitch:

Sunscreen is an essential tool in staying young and healthy. Sun damages our skin and makes us look older than we are. Before you decide It’s too late (oh yeah, I’ve heard that one before), it’s not. It’s never too late.

In fact, that’s sort of the theme of my blog. Start now. Don’t wring your hands over yesterday, we can’t get a do-over. But you CAN start today!

Now, that we are all united in our We shall wear sunscreen every blessed day for the remainder of days attitude, let’s proceed to de-mystify the math.

The smarty pants in the world have calculated for us that FDA’s requirement of 2mg/cm² equals about 1/4 tsp of sunscreen for an average sized face/neck. Then we cope with the qualification that not everyone has an average sized face/neck. (That certainly triggers some insecurities for me!)

If you do a search for this, you’ll find recommendations that range from 1 shot glass full for the whole body to 1/4 – 1 teaspoon for the face/neck/chest.

I reviewed all of recommendations from skincancer.org and American Cancer Society, to the FDA, Consumer Reports, and a variety of dermatologist sites world wide. I am simplifying this nonsense so it works for us all. We aren’t one size fits all, but here’s a starting point for us – at least in a way that made sense to MY brain.

Sunscreen By the Numbers

Please refer to the numbered diagram above.

1. For the face and neck – use 1/4 teaspoon.
   I actually bought a 1/4 tsp measuring spoon [affiliate link] to help me out. You will find many people double this, but they include the chest. I broke it out so we concentrate on our chest separately. Most of us show sun damage here which makes us look less fresh and dewy than we feel.
2. For the chest – use 1/4 teaspoon.
3. For the front torso – use 1 teaspoon.
4. For the back (including neck) – use 1 teaspoon.
5. For the arm – use 1 teaspoon.
6. For the other arm – use 1 teaspoon.
7. For the leg – use 1 teaspoon.
8. For the other leg – use 1 teaspoon.

If you’re curious (I was) a shot glass equals about 9 teaspoons. My measurements above equal 6 1/2 teaspoons. If you need more, use more…but please, don’t use less. The 6 1/2 teaspoons is your baseline.

A few more things to remember, while we are on the topic of sunscreen:

1. Use sunscreen every day. Every. Single. Day.
   (Even on days when I’m staying in doors?) Yup! Even then. If there are windows, you can get exposed to UVA/UVB. And please wear it when you fly!
2. Use at least an SPF of 15.
   I apply SPF 50 on any part of my body I want to stay looking young. Think about that and make your own choices. We’ll talk some other time about the confusing, nonsensical world of SPF numbers.
3. Reapply throughout the day.
   I’ll admit it…I suck at this, but I have a chance to improve every day. Are you with me? The experts say every 2 hours. Absolutely follow this rule when you’re outside and active.
4. Use the correct amount.
   Just trying to drive this home. If the shot glass method works for you, power to you. I found the measuring spoon method helpful to acclimate me to the proper amounts.

I have some favorite sunscreens I’ll share with you in another post. In the meantime, what questions have you always had about sunscreen? Does it confuse you as much as it confuses me?

Disclosure: I am a participant in the Amazon Services LLC Associates Program, an affiliate advertising program. Some of these links are affiliate links. If you click a link and buy something, I may receive a commission for the sale. It does not cost you anything extra and you are free to use the link or not. Product purchases for review are made with my own money and my opinions are my own. If product is ever provided or the article is sponsored, it will be clearly noted at the top of the page.